This invention relates to a mineral mining installation, and in particular to an installation for winning material such as coal.
In place of conventional winning machines such as coal ploughs or shearers (which win coal mechanically), it is known to use machines which win coal by hydraulic pressure. Typically, such a machine has a plurality of nozzles which are fed with hydraulic fluid under a high pressure of 400 to 1,000 bars or even higher. Usually, the hydraulic fluid is water, though other fluids could also be used. One known hydraulic winning machine has a drum provided with high-pressure nozzles on its circumference, and another has a plough body provided with high-pressure nozzles in place of plough cutter bits (see DT-OS No. 2548951 and DT-OS No. 2307413). It is also known to provide a plough body with high-pressure nozzles as well as cutter bits (see GB-PS No. 672,336). In this case the plough body is provided with a high-pressure pump which raises the pressure of hydraulic fluid from that of the supply to that necessary for the hydraulic winning work.
Unfortunately, the known types of hydraulic winning machines suffer from difficulties which have prevented them from becoming established as practical devices. In particular, such machines require a very large input of water, and difficulties arise in the production and feed of high-pressure water to the nozzles of a high-speed winning machine.
The aim of the invention is to provide a winning machine which utilises the hydraulic winning method but does not suffer from these disadvantages.